A successful endodontic treatment depends upon localization, proper chemo-mechanical preparation of the root canal system, debridement, shaping, disinfection, and three-dimensional obturation of the canal system. To achieve this, endodontic therapy used to be performed in multiple visits for complete disinfection of the canals. Single-visit endodontics is defined as "the conservative non-surgical treatment of an endodontically involved tooth consisting of complete biomechanical cleansing, shaping, and obturation of the root canal system during one visit". In the era of modern endodontics, it is important to view single-visit endodontics as a supplemental procedure that compliments total patient care. The concept of single-visit root canal treatment is based on the entombing theory, which the large number of microorganisms removed during cleaning and shaping and the remaining bacteria entombed by the root canal obturation, therefore it will miss the essential elements to be survive nutrition and space.